Revelation is the act of revealing or disclosing, or making something obvious and clearly understood through active or passive communication with the divine. Revelation can originate directly from a deity, or through an agent, such as an angel. One who has experienced such contact with or communication from the divine is often known as a prophet.

Some religions have religious texts which they view as divinely or supernaturally revealed or inspired. Revelation or information from a supernatural source is of much lesser importance in some other religious traditions. It is not of great importance in the Asian religions of Taoism and Confucianism, but similarities have been noted between the Abrahamic view of revelation and the Buddhist principle of Enlightenment.

Epistemology: How does one know if a divine revelation is in fact genuine?

In earlier eras it was taken as a given by many people that God, or the gods, revealed His (or their) will to mankind in some form or another. Since the dawn of classical modern philosophy, and especially since the Age of Enlightenment (circa 1700-1800s CE), this belief has become less well-accepted among a growing segment of the population.

This question is part of the subject of epistemology. Epistemology is the branch of philosophy that addresses questions such as: "What is knowledge?", "How is knowledge acquired?", and "How do we know what we know?" In addressing this subject the first issue to note is that the terms "knowledge" and "belief" are often used interchangeably by religious believers, but technically these are very distinct terms.

Often, statements of "belief" mean that the speaker holds a religious belief to be true, although firm proof is lacking. Examples would be the belief that God created the universe, or that God sent a message to the biblical prophet Isaiah. Some religious believers hold that they actually have proof that such beliefs are true, but these proofs are not agreed upon by people within any one religion; they are certainly not agreed upon by people outside of their religion, and they are rejected as proof by both philosophers, logicians and scientists. It is precisely the belief in things which cannot be proved that forced philosophers to ask "What is the difference between belief and knowledge?" This had led philosophers to discover that knowledge differs from belief, in that knowledge is a justified, true belief. (This is an over-simplification, see the article on epistemology and the Gettier problem.)

Abrahamic religions, including Judaism, Christianity and Islam, take it as a matter of faith that God exists, and in some way can reveal His will to people. However, the question of epistemology still exists among members of those faiths, as members need to be able to distinguish between true prophets and false prophets. There are documents in each of these religions which offer criteria with which to distinguish true from false prophets.